Dec. 10, 1946. 2,412,316 J. F. CAMPBELL FUEL INJECTION SYSTEM 4` *Sheets-Sheet 1 Filed Jail. 16. 1942 ¿Ecampßgzz INVENTOR BY Den.` l0,l 1946; I J. F. CAMPBELL FUEL. INJECTION 2,412,316 SYSTEM Filed Jan. 1e. 1942 ' 4 sheets-sheet 2 Z R94 @XE e "JF Cam/06e!! Dec. l0, 1946. ‘ ,2,412,316 J. F. CAMPBELL 1 FUEL.` INJECTION SYSTEM - Eiléd Jan. 1e. -194,2 ‘4 Sheets-Sheet 5 ¿Ecm/7662i INVENTOR - ATTORNEY Dec. 10, 1946. 2,412,316. J. F. CAMPBELL `FUEL INJECTION SYSTEM Filed Jan. 16. 1942 4 Sheets-Sheet 4 -a.-iufÍs.L . L. mw. . .Y ....E. “ INVENTÓR BY ATTORNEY ¿mais ‘L ` 2,412,316 sont mlaorrou SYSTEM .lohn F. Campbell, Detroit, Mich., asslor to ' George M. Holley and Earl Holley Apo-lisation .lanuary lt, i942, Serial No. 4126A??? l Il Claims. l (ci. its-37) ' 2 , shown in the upper right hand corner of Fig. 1 The object of this invention is to inject volatile is shown on a greatly enlarged scale but is ac fuels or fuels containing air bubbles by means of tually of the same order of magnitude as the ven a plunger into an internal combustion. engine. turi 35 and has merely been enlarged so as to The specific object is to permit the bubbles of air clearly indicate the nature of the restriction i3 and vapor to escape before injection of the fuel which corresponds to the venturi liti as shown in without interfering with the metering character my Patent No. 2281,@11, Fig. l2. ln Fig. l2 of this istics of the fuel injection pump. In fuels of the patent, the venturi fili is also shown in a large volatile type it is customary to use spark ignition scale for a like reason. f and therefore, the time of ignition is not deter. Considering the details shown in Figs. 2 to 7, mined by the time of the fuelginjection. With lil lb is the fuel entrance as mentioned above, which such pumps, l' have found that it is desirable to delivers fuel to the cylinders itl. In these cyl have a fixed point of cut-obi’ prior to the ignition inclers' are two diameter-ed plungers 2@ recipro point and therefore, I regulate the amount of fuel cated by theinclined swash plate 2l (Fig. 2) by by the variable point in the pumping stroke .of the means of the oblate spheroid 22 of .the plungers pump when the escape of the surplus fuel and fuel 2u. Each plunger has a tubular extension 23. ofV a carrying the vapor is prevented. As the plunger smaller diameter than the main piston it. . Each moves beyond the initial point the fuel is injected of these tubular extensions 23 engages with a into the engine cylinder'until the 'fuel pressure is movable yielciable abutment Zit. Each ci these suddenly released. In the drawings: 20 yieldable abutments Wl is loaded by two springs Fig. l shows diagrammatically the arrangement of all the elemente of my invention. ` _ 2t and 2l. These springs are located in a cham- A ber l@ and seat on a ñange 2li which, in its turn, seats on the movable abutment tél.. The abut ments of the springs are carried in c, cage 2t, on Fig. 2 shows the principal element-_the fuel puma-#on a section of plane 2--2 of Figs, 3 and '7. Fig. 3 is a cross sectional plan view taken on 25 the lower ñange of which the abutments 213 seat when the tubular extension 23 of the piston i@ is plane 3_3 of Fig. 2. ` withdrawn into the cylinder le, es shown on the Fig. e is a plan view teken on plane fis-ä of left hand side of Fig. 2. On the right hand side Flg.2. '~ ' of Fig. 2, the piston lo ls shown elevated carrying Fig. 5 is a plan view taken on plane â--El of « Fis'. . ' FiFig. 6 is a plan view takenon plane ë-ë of e. . . Fig. ‘TI is a plan view taken on plane ‘l-l of with it the tubular extension 23 which thusV com- ' presses` the springs 2e, 2l by engaging with and - moving the movable a-butments lt. vThe cage 2B is reciprooated relative tothe cyl- ' inders le. Means for reciprocating it consists of a Fig'. 8 is a sectional elevation of a modification 35 lever 2@ which rotates the shaft il@ which engages with the shaft ill. Grooves 3i! are provided on ofFig.2. shaft @l adapted to move the pins-3 l, il which are Fig. 9 shows a cross sectional elevation of the mounted on the cage 23. The cage 2@ is thus vapor separator. moved when the shafts il@ and iii are rotated com' Fig. l shows diagrammatically the arrange pressing the springs 2l and 25. The spring 3S bal ments of the parts. Fuel leaves a tant: lo and is onces in part the resistance of these springs 2t raised by a‘pump l l to the fuel/air mixture ratio and 2l. ' control l2 'which contains a fuel venturi iii. The The rotation of the lever 2S thus determines the -fuel flows through a second venturi it to the vapor eîective ich of the stroke of the two diametered separator i5 whence it continues through a pipe t@ to the fuel entrance l@ of the metering pump il. 45 plungers 2t when their tubular extensions ‘23 en gage with the movable abutments 2t which is the Here a minor portion issues into a chamber @il moment when the plunger â starts to deliver fuel where the vapor rises to the upper part of this to the nozzle, assuming that> the piston 2o has chamber 3ft.4 The major portion of the fuel dis Fig.2. - . covered the port il@ before the part t3 engages charges through the'outlets it. The minor irac ' l tion of the fuel in the chamber lil is recirculated 50 with the part le. The tubular extension 23 is perforated so that through the opening ââinto the throat of the ven as the plunger E@ moves towards the movable turi §55 back to the vapor separator i5. This re abutments 2li any fuel containing air which is circulation of the fuel ensures the elimination of trapped in the annuler portion between the tu entr aimed bubbles which disturb the metering characteristics oi the pump. The venturi it 55 bular extension te and the walls of the cylinder 4, 3 I9` discharges through the center of' the-tubular y . is either vertical or horizontal, it is arranged so lthat the venturi y¿I4 is on the top side of the verti . extension 23 and along the flutes of the guide to.; cal or horizontal pump chamber. As the pump -the valve 24 which centers the valve 24 inside the central passage through the tubular extension 23. The moment the fuel is trapped in the cylinder I9, lthat is, the momentl the tubular extension 23 en gages with the movable abutment 24, fuel is sub «operates any bubbles that may collect in the `chamber 3_4- are automatically removed tothe vapor separator I5 by means of the venturi I4. When the engine develops over 50% of its power, ' the amount of fuel flowing through the passage ‘ ` jected to pressure and in Fig. 4 is shown a. number 35 is 20% or more of the total quantity of fuel l of spring-loadedchebk valves 32. Fuel then dis charges~through the passages 33 and flows down 10 thatv enters the fuel entrance I6. Hence this por- l tion of the fuel is re-circulated and carries vwith ‘ to the outletl passages I8, whence it is led to the nozzles on the engine (not shown)._ Now -the it the bubbles of vapor and air to the vapor sep chamber 34 which contains the springs 26 and 2l `\ - arator I5. By _this means _the cylinders are main tained >full >of >.fuel so> that the amount of fuel ‘ and the cage 28 communicates with the throat o-f . the venturi I4 (Fig. 3), through a Passage 35 discharged».»by,_~feach nozzle isunlform, and the ' ‘ whence it is carried to the vapor separator I5 ` vapor ceases to'jbe an objectionable feature as'it is largely removed through the vapor _separa (Fig.3). The fuel surrounding the springs 26 and 21' is tor agitated by the reciprocation of these springs,` I5. - ’ ' . ' f The effect of the re-circulation of a portion of bubbles Aof vapor are released and these bubbles 20 the fuel is that the fuel admitted first tothe pump chamber, that is th'e fuel which enters into escape through the venturi I4 located above theK ‘ chamber 34. , a p_artial'vacuum and is most likely to release ' vapor bubbles, is rejected through the passage 54 (Fig. 8) and past the valve 24 (Fig. 2). The piston 20'is provided with a number of ` >small holes 'I communicating `with an annular l The reason the fuel flows into the chamber 34 . passage B0 which has an outlet port 51 and when 25 and not back into the annular chamber 42 is be this port` 51- rises, as shown on the right hand cause the pressure in the chamber 34 is main ` side- of Fig. 2, it is in alignment with the cylinder tained below the pressure in 42 by means of the ' port 58 and the discharge of the fuel abruptly ceases, the fuel escaping into the annulus 42. venturi I2. The mode of_ operation of the> modification In Fig. 8, the pump elements 20, 23‘ of Fig. 2 30 vshown in Fig. 8 and that of the device shown in are modified as follows: The-part 50 of Fig. 8 Fig. 2 is substantially identical. In both cases, l corresponds to the part 20 of Fig. 2 and the part the escape of fuel into the chamber 34 is abruptly 22 corresponds to and is identical with the part marked 22 of Fig. 2. The »plunger 50 has a valve terminated when the cut-off valve »seats and . seat 5I which engages with a coned valve sur 35 thereafter the fuel is compressed and discharged into the cylinder until such time as the groove l face 52 which forms the lower end of` a small 57 in the plunger is in line with the annular piston 53. In the center of this small hollow groove 68 in the cylinder which determines the . ï valve is a passage 54 through which fuel can > freely-discharge before valve 52 seats'on valve seat_5l'. The'small hollow-valve 53 carries the 40 end of the injection stroke. In the construction shown in Fig. 8, fuel enters ~ `from the annulus 42 and is first rejected through the passage 54 and a portion of the fuel is then trapped between the piston 50 and the piston l53 ' " by the springs 26, 21, and the element 25 of Fig. 2, when the valve seat 5I~ engages the -hollow valve l which it is not necessary to show again as the function is the- same. This shoulder 28 as al 45 53 `having a'seat 52.. This portion of the fuel which is thus trapped is then injected through ya ' ready described can vbe moved by means of the passage corresponding to the passage 33 of Fig. 2, pinsl 3|, 3l and the slots 30, 30. Hence the small.y until such time as the slot 51 comes into-align ,hollow valve 53 forms a variable cut-ofi` for thel -piston 50. A bushing 56 forms a bearing for the ment with the annular passage 58 when the pres small piston 52. ' 50 sure is suddenly and completely released.- It fol-V An annular opening 51 in the -piston 50 is con lows, therefore, thatas the valve seats (5I in Fig. 8 and 24 in Fig. 2) are moved back and forth ‘ nected by a-number of small holes 59 to the top by the rotation of the lever 29, the time at which face of thepiston 50. The result is that the _small injection commences varies, but there is a fixed v holes .59 servîe.. as a by-pass so that when the piston 55 has~ completed its stroke and the annular 55 point of cut-oñ determined by the instant when the slot 51 in the plunger comes into line with ì opening- 51 is in alignment with the'a'nnular port collar 55 which'seats on the shoulder 28 and this ` collar 55 is compressed against the shoulder 28 `58 of the cylinder, vthe discharge of the fuel the cylinder port 58. abruptly ceases. `What I claim is: - ` . « l ' l. In a fuel injectionv system for an internal In Fig. 9, the vapor separator I5 is shown in greater detail. The surplus fuel enters the venturi 60 combustion engine, a supply of fuel under pres- j ’ sure, a vapor separator, a/ vapor separating tank, I4 throughÍ the entrance 35. leaves through the a pump chamber, a fuel entrance communicating passage 6I, and then past the baille 82 into the with said fuel supply and leading to said vapor-float chamber 63 in which a float 64- carries a separator and communicating with _said separat _slide valve 65 which permits air andva'porl‘to . escape through the outlet 66. The fuel thus freed 65 ing tank, a fuel outlet from said separator forni from vapor escapes »past the screen 61 'into the , ing the entrance to said pump chamber, means outlet 68 and then through a pipe 69 to the en trance I6. Of course, the vapor> separator _I5 can be built as an integral part of theupper casing 70 35 of the fuel pump. ing tank than in thev fuel entrance to the pump chamber, a plunger, means for reciprocating said plunger, a valve seat integral -with said plunger, ` ' Operation ` The _device is mounted so that the venturi I4 is located above the vapor separating chamber.,` for maintaining a lower pressure ‘in the separat-` ` ’ a hollow cylindrical valve in alignment with said seat of smaller diameter than said plunger and -adapted to'permit'surplus` fuel to ñowthrough - it to said separating tank, means for moving said that is to say, whether the device shown in Fig. 2` 75 valvel so 'as to engage withl said valve seat _at 2,412,816 different points _in the stroke-of said plunger so as to interrupt the release of surplus fuel, yield ing said plunger, a hollow cylindrical extension of said plunger having a valve seat in the end, able means to permit the valve to move with said a valve engaging with said valve seat and in plunger after it has seated thereon, a relief pas sage in said plunger, a relief port in the side of> alignment therewith and adapted to permit sur plus fuel lto flow from the pump chamber to the said plunger, an inlet port tothe cylinder adapted separating tank, the diameter of said cylindrical to engage with the relief port in said plunger towards the -end of the pressure stroke of the pump, and also adapted to be uncovered by -the end of the plunger’when it is near the end of its 10 extension being less than> the diameter of said plunger, adjustable means for locating said valve so that‘it engages with said extension at differ ent points in the stroke of the plunger, yieldable means permitting the valve to move with said extension after it has seated, a relief passage in said plunger, a relief port in the side of said suction stroke, an outlet port lfrom the cylinder, a check valve therein, whereby the plunger on its down stroke first uncovers the inlet ports and plunger, an inlet port to the cylinder adapted tl. thereby permits fuel to flow through the cylinder and past the valve to the separating tank under 15 engage with the relief port in said plunger toward the end of the pressure stroke ofthe pump and the pressure difference between the separating also adapted to be uncovered by the end of- the tank and the fuel entrance and whereby after ' this port is covered by the plunger on its in stroke, fuel is then forced past the valve to the separat ing tank and whereby after the plunger engages with the hollow valvel fuel is trapped and thereby ejected through the outlet port past the check valve and this discharge continues until the relief port of the plunger engages with the inlet port larger diameter of the plunger when it is near the end of its suction stroke, an outlet port from ' the cylinder, a check valve' therein, whereby the plunger on its down stroke ñrst uncovers the inlet ports and thereby permits fuel to flow through the cylinder and through the hollow-valve to the separating tank under the pressure difference be- - of the cylinder when the discharge ofl fuel is 25 tween the separating tank and the fuel entrance and whereby after this port is covered by the abruptly terminated. ' plunger on its in stroke, fuel is then forced 2. In a device as set forth in claim 1- in which through the hollow valve to the separating tank the means for maintaining a lower pressure in and whereby after the. extension of the plunger the separating tank consists of a venturi in the fuel line and an opening in the throat of the ven 30 engages with the valve fuel is trapped and thereby ejected through the outlet port past the check turi communicating with the separating tank so valve and this discharge continues until the relief as to return the surplus fuel to be re-circulated, port of the plunger engages with the inlet port 3. In a fuel injection system for an internal of the cylinder when the discharge of fuel is combustion engine, a su'pply of fuel under pres sure, a vapor separating tank, a vapor separator, 35 a pump chamber, a fuel entrance communicating abruptly terminated. e. In a device as set forth in claim 3 in which. the means for maintaining a lower pressure in the separating tank consists of a venturi in the fuel line and' an opening. in the throat of the with said fuel supply and leading to said vapor separator and communicating with said separat ing tank, a fuel outlet ,from said separator form ing the entrance leadingto said pump chamber, 40 venturi communicating with the separating tank means for maintaining a lower pressure in the so as to return Athe surplus fuel to be re-circulated. separating tank than in the fuel entrance to the pump chamber, a plunger, means for reciprocat JOmî F. CAB/IPBELL.